1. Field of the Invention
The present invention relates to a laser apparatus that uses many laser diodes (LD) as laser light sources or excitation light sources for laser oscillation, and a machine learning apparatus and a machine learning method for learning data relating to LD driving conditions of such a laser apparatus.
2. Description of the Related Art
In a high-output laser apparatus using an LD, many LDs may be used. Therefore, a plurality of laser diode modules (LDM) including at least one LD are prepared. Typically, the laser apparatus includes a plurality of LDMs, and is provided with a plurality of independently drivable laser diode units (LDU, LD unit).
In the laser apparatus using the LD, it is significant to know a remaining life of the LD, and there are a plurality of documents on conventional technologies. The remaining life means a life remaining until its end. However, the remaining life may vary depending on subsequent driving conditions of the LD. The remaining life herein means a remaining life when the laser apparatus is driven on a standard driving condition.
For example, Japanese Unexamined Patent Publication (Kokai) No. 8-279642 discloses that “the life of the light emitting element is predicted by using a driving current value for emitting a specific optical output as a reference value and a driving current larger by n times than the reference value as a deterioration threshold current for replacing the light emitting element”.
Further, Japanese Unexamined Patent Publication (Kokai) No. 2005-294493 discloses that “control is performed so as to keep constant an output of each laser oscillator and set power at the processing point equal to predetermined power, and the life of the excitation LD is predicted”.
Further, Japanese Unexamined Patent Publication (Kokai) No. 2005-317178 discloses that “time-sequential data relating to the increase of a generated heat amount caused by deterioration of the semiconductor laser is created, and the life of the semiconductor laser is predicted based on the time-sequential data relating to the increase of the generated heat amount”.
Further, Japanese Unexamined Patent Publication (Kokai) No. 2006-222411 discloses that “the life of the excitation light source is estimated by using a current value supplied from the power source to the excitation light source when a signal output from the power sensor satisfies a predetermined condition and an operation time stored in the memory”.
Further, Japanese Unexamined Patent Publication (Kokai) No. 2011-86496 discloses that “a characteristic variation amount that is a difference between current intensity characteristics deteriorated due to use and ideal characteristics is compared with an allowable variation amount to predict a replacement timing of the laser light source”.
Further, Japanese Unexamined Patent Publication (Kokai) No. 2012-15440 discloses that “when cumulative time of time points when a driving current exceeding a predetermined deterioration threshold current flows through the laser diode exceeds a threshold time preset for each ambient temperature, the life of the laser diode is determined to be nearing its end”.
Further, Japanese Unexamined Patent Publication (Kokai) No. 2005-317841 discloses that “by using a driving current time product, the deterioration degrees of the laser diode elements 1a, 1b, and 1c can be managed in a form appropriate to an actual situation”.